Portion of a footwear sole



FIG. 1 is a perspective view of a portion of a footwear sole, showing my new design; and,

FIG. 2 is a bottom plan view thereof.

The broken lines in both figures show the environmental context for the design, but form no part of the claim. The left side forms no part of the claimed design. 

The ornamental design for a portion of a footwear sole, as shown and described. 